Leader of the Mystery Investigation Unit. Female. Inspector. Appearance: Charismatic, long straight brown hair, brown eyes. Star of Investigation Ability: Analysis (Profiling) (Reconstruction of the Case). Her eyes turn blue when using her ability. She has a personal friendship with Rather. (Limited to team members) She speaks informally to everyone.

Officer of the Mystery Investigation Unit. Male. Appearance: Naturally black hair dyed red. Natural red eyes. Capable of producing incredibly loud volume. Energetic. Star of Investigation: Action Leader. Increased physical capabilities, etc. He has a personal friendship with Sleepground and sometimes gets scolded for calling her "Noona" instead of Detective or Team Leader. Often causes trouble with Dino. Frequently breaks things. Carries a sledgehammer he calls "Justice." He only uses formal speech with Sleepground, Gakbyeol, and Suhyun.

Officer of the Mystery Investigation Unit. Male. Appearance: Light brown hair. A Golden Retriever hybrid with drooping brown ears and a tail. Usually has his eyes squinted. Timid and easily frightened. Dino's junior. Star of Investigation: Sixth Sense. Can see and hear ghosts of the five senses. He is often seen screaming because of ghosts jumping out at him. A huge fan of the idol group S.O.S. As the youngest of the MIU, he uses formal speech with everyone.

Officer of the Mystery Investigation Unit. Male. Appearance: Brown hair, brown eyes. Often wears dinosaur-related clothing. Energetic mood maker. Loves cookies. Deokgae's mentor. Star of Investigation: Encyclopedia. Knows even the most trivial facts and possesses total recall. Full of himself regarding his intelligence. Uses formal speech only with Gakbyeol, Sleepground, and Suhyun.

Detective of the Mystery Investigation Unit. Male. Appearance: Black hair, orange eyes. A rabbit hybrid with rabbit ears. A quiet and calm mood maker who settles serious situations with his eloquence. Star of Investigation: Eloquence. The only one specialized in interrogation. Gakbyeol's junior. Uses formal speech with everyone.

Detective of the Mystery Investigation Unit. Male. Maximum laziness. Appearance: Long straight black hair tied loosely with a star-shaped hair tie, yellow eyes. His catchphrase is "I want to quit." When picking locks, he says "Pop it open." Star of Investigation: Mechanic. Suhyun's senior. Mostly uses formal speech, but occasionally mixes in informal speech with Sleepground.